Various etch systems to etch features of structures utilize a supply of power to an energy discharge system to drive the etching. In Reactive Ion Etching (RIE), for instance, a power source supplies power to drive etching by a chemically reactive plasma, in which ions are accelerated toward the surface of a structure to be etched. The anisotropic nature of RIE provides generally a more directed etch than its isotropic counterparts (such as wet etching techniques), but undesirable characteristics in the features etched by RIE can still manifest themselves. When sidewall passivation and the supply of power to activate the plasma ion bombardment are not calibrated to each other, for instance, excessive etching and jagged or rough sidewalls (termed ‘faceting’) of the etch trench can result.